1. Field of the Invention
This invention relates to a shut-off unit for stopping a drive unit which is to drive a tubular shaft upon which is to be wound an awning or a roller blind.
2. Description of the Prior Art
Shut-off units of the above type are typically required to stop the drive unit in at least two defined end positions corresponding to the desired end positions of the element being wound. In one particular type of known shut-off unit, the unit is adapted to be arranged at a first end of a drive unit of a type which is additionally comprised of the following individual elements arranged axially one behind the other proceeding in a direction away from the shut-off unit: a capacitor, an electric brake, an electric motor, a step down gear and an output shaft. More specifically, this known type of shut-off unit comprises a so-called spindle drive in which spindles are driven via an internal gear which is in engagement with the tubular shaft being driven by the drive unit. Carried on the spindles are lobes which are moved axially and which actuate end switches for switching off the drive unit when the desired end positions are reached.
It is object of the present invention to provide a shut-off unit of the above type which has shorter mounting dimensions, is easy to install and is operationally reliable.